Process for preparing amorphous copolymers from ethylene and higher alpha-olefins by means of modified organometal mixed catalysts

ABSTRACT

PROCESS FOR PREPARING RUBBER-LIKE AMORPHOUS COPOLYMERS OF ETHYLENE WITH A-OLEFINS IN THE PRESENCE OF MODIFIED VANADIUM-CONTAINING MIXED CATALYSTS CONTAINING AS REACTIVATOR HALOGEN-CONTAINING, ALKYL-SUBSTITUTED B-LACTONES. THE CATALYST YIELDS RE SO HIGH THAT IN THE CASE OF THE PREIPITATION POLYMERIZATION THE POLYMERIZATION MIXTURE CAN BE WORKED UP BY SIMPLE FILTRATION. THE POLMERS HAVE A LOW ASH CONTENT AND ARE CHEMICALLY AND PHYSICALLY VERY UNIFORM. THE VULCANIZATION PRODUCTS MADE THEREFROM HAVE IMPROVED MECHANICAL PROPERTIES.

March 7, 1972 H. SCHAUM 3,647,768

PROCESS FOR lHlh'PARlNG AMORPHOUS COPOLYMERS FROM ETHYLENE AND HIGHER-0LEFINS BY MEANS OF MODIFIED JRGANOMETAL MIXED CATALYSTS Filed. Sept.27, 1968 2 Sheets-Sheet 1 FIG. 1

? [gram polymer/millinole VCCl HCPL Jmolor rutlo] H INVENTOR HELM UTSCHAUM BY M l W W ATTORNEYS Marchj, 1972 r SCHAUM 3,647,768

PROCESS FOR PREPARING AMORPHOUS COPOLYMERS FROM ETHYLENE AND HIGHER-OLEFINS BY MEANS OF MODIFIED ORGANOME'I'AL MIXED CATALYSTS 2Sheets-Sheet 2 Filed Sept. 27, 1968 FIG. 2

[gram polymer/millimole V0Cl TCPL vocl 3 0M0] A INVENTOR HELMUT SCHAUMBY M,MW

ATTORNEYS 3,647,768 PROCESS FOR PREPARING AMORPHOUS COPOLY- MERS FROMETHYLENE AND HKGHER a-DLE- FINS BY MEANS OF MODIFIED ORGANOMETAL MIXEDCATALYSTS Helmut Schaum, Bad Soden, Taunus, Germany, assignor toBunawerke Huls Gesellschaft mit beschrankter Haftung, Germany FiledSept. 27, 1968, Ser. No. 763,215 Claims priority, application Germany,Oct. 5, 1967,

ABSTRACT OF THE DISCLOSURE Process for preparing rubber-like amorphouscopolymersof ethylene with a-olefins in the presence of modifiedvanadium-containing mixed catalysts containing as reactivatorhalogen-containing, alkyl-substituted B-lactones. The catalyst yieldsare sol-high that in the case of the precipitation polymerization thepolymerization mixture can be worked up by simple filtration. Thepolymers have a low ash content'and are chemically and physically veryuniforlrnrTheiiulcanizationproducts made therefrom have improvedmechanicalproperties;

From Belgian Pat. 553,655 it is known to convert ethylene together withhigher u-olefins into high-molecular copolymers by using organometalmixed catalysts known as Ziegler Catalysts and used in industrialpractice, under pressures in the range of from to 3 atmospheres gaugeand at temperatures in the range of from 30 C. to 150 C. (so-called lowpressure process).

When relatively high proportions of higher a-olefins are used (aboveabout 25% by weight) the copolymers obtained according to theabove-mentioned process are amorphous and can be used as rubber. Therubber-like copolymers containing a considerable proportion of highera-olefins are soluble in aliphatic, aromatic and cycloaliphatichydrocarbons and in some halohydrocarbons, for example, carbontetrachloride, tetrachloroethylene and trichloroethylene.

The monomer mixture is in most cases polymerized in the specifiedsolvents so that the copolymers are obtained in the form of highlyviscous solutions (solution polymerization).

It is likewise known to modify the catalysts by using small amounts ofadditives.

According to Belgian Pat. No. 652,010 amorphous copolymers are producedby copolymerization of mixtures of u-olefins, if desired with diolefins,in a homogeneous phase with the aid of modified organometal mixedcatalysts obtained by reacting vanadium compounds that are soluble ininert organic solvents with organo-aluminium compounds and an aliphatichalogen compound of the general formula C(X) Y wherein X represents ahalogen atom and Y is a radical of the following composition:

fees, gov rn ,oa'".

whereir'rR' and-R represent the following groups: -halogen, '-alkyl,-halogenalkyl, -aryl, -h alogenaryl, -alkaryl, R represents -alkylene,R'" represents -alkyl, -halogenaIkyL-aryl, -halo'ge'nar yl, -alkaryl andZ is hydrogen, halogenalkyl, aryl and 'halogenaryl, Z and Z" arehalogen; halogenalky], alkyl, aryl and halogenaryl.

Furthermore, Belgian Pat. 628,896 discloses the preparation of amorphouscopolymers of ethylene and u-olefins by using catalysts ofdialkyl-aluminium halides and addition complex compounds of vanadiumhalides with a Lewis base, for instance with complexes of VC1 VC1 orVOCl with diethylether, diisopropylether, diethoxy-ethane,tetrahydrofurane and dioxane.

It has also been proposed to carry out the copolymerization in liquidsthat do not dissolve the polymer. The number of suitable dispersionmedia is, however, limited because most of the dispersion media forthese rubber-like copolymers react with the catalyst which thereby losesits activity.

British Patent 849,112 proposes the use of halohydrocarbons, for examplemethylene chloride, ethyl chloride, 1,2-dichloroethane and1,l,2-trifluorotrichloroethane for preparing suspensions of saidcopolymers.

British Patent 925,468 proposes as suitable solvents for the preparationof suspensions of rubber-like copolymers of the aforesaid kind methylenechloride, ethyl chloride and 1,2-dichloroethane and uses polymerizationtemperatures which exceed neither the boiling point of said solvents nor50 C. According to the above-mentioned patent the copolymers are workedup exclusively by extracting the catalyst with water after interruptingthe polymerization with alcohol or water.

In order to avoid the industrially complicated working up it has beenhighly desirable to develop a process in which the catalyst efficiency,i.e. the yield calculated on the amount of catalyst used, is improved toan extent such that the catalyst may remain in the product withoutextraction while the solvent can be separated off by filtration and canbe re-used without further purification, and the major proportion of theorgano-aluminium compound of the catalyst is preserved for anotherpolymerization. This is only possible, however, if the polymer yield issubstantially increased with respect to the amount of catalyst used.

Now we have found a process for the copolymerization of ethylenetogether with a-olefins of the formula wherein R represents a branchedor straight-chained aliphatic hydrocarbon radical having less than 7carbon atoms, and, if desired, together with a diolefin in an amountsuch that the terpolymer formed has an iodine number not greater than50, in the presence of inert solvents or dispersing media, thecopolymerization being carried out under pressure in the range of from 0to 30 atmospheres gauge and at temperatures in the range of from 30 toC., with coordination catalysts of 3- to S-Valent vanadium compounds andorgano-aluminium compounds, both soluble in the dispersing agent used,with stirring or other mechanical agitation, which comprises carryingout the polymerization.

(1) By using the vanadium compounds in concentrations in the range offrom 0.001 to 0.1 millimole per liter of dispersion medium,

(2) By using organo-aluminium compounds the molar ratio of aluminium tovanadium of which being in the range of from 20 to 200, preferably 30 toand for instance, a ,B-trihalogenomethyl-B-lactonewherein (3) In thepresence of halogen-containing, alkyl-substituted fi-lactones asreactivators, the molar ratio of.re

from 5 to 100, preferably 5-20.

The addition, according to thepresent invention, of,

halogen means fluorine, chlorine or bromine-produced according to one ofthe processes named in the following table sub 14, increases the polymeryield about 2 to 3 times. When applying the solution polymerization aswell gen, preferably chlorine, and n is 1 to 3. There are mentioned, forexample, Al(C H,-,) Cl, Al(C H )Cl Al(i-C H )Cl Al(C I-I and Al(i-C HPreferably there are used compounds corresponding to the formulaPreparation Formula Abbreviation Literature (3013 CCls-0 TCPL 0., uncat.C=O H2C=C=O L H/ 70% O C 013 190 0 t C C1: HCPL unca 0:0 Hzozozo 807C613 0 o 013 0 L 0013 E 0 CCla-0 DMTCPL (1) 15 0., BFa-etlierate 0:0C=C=O 6 CHS 11 E 0 CH3 F 0 GHQ-0O CFs I-IFPL 26% l F30 CHr-C O :0

Wherein represent:

TCPL=fl-trichloromethyl-fi-propiolaetone. HCPL=fl,fi-bis-trlchloromethyl-B-propiolactone. DMTCPL=a,adimethyl-B-trichlorornethyl-fi-propiolactone. HFPL=B,B-bis-triflnoromethyl:B-propio1actone. 1 H. Ohse, R. Palm and H.Cherdron, Monatshefte der Cheinie, in print. E. Schimmedlschmidt and E.Mundlos German Patent 1,136,323

The products obtained by using this modified catalyst system showproperties that are of great advantage in industrial practice, forinstance, higher vulcanization velocity and better confectionadhesiveness. Due to their being easily accessible the reactivatingcompounds used according to the process of the present invention areparticularly suitable for the purpose in question.

The halogen-containing, alkyl-substituted ,B-lactones are a constituentof the catalyst and are not incorporated into the copolymer as could bedemonstrated by infrared spectroscopic analysis of polymers purified byreprecipitation.

The process according to the present invention is of particularadvantage when materialized in precipitation polymerization. The highcatalyst efficiency attained by using these reactivators, with theindicated amounts of catalyst, the specified ratio of the catalystcomponents and the solvents not or only slightly dissolving the rubber,enables the polymerization batch to be worked up without the addition ofwater by filtration, so that it is not necessary, as in the hithertoknown processes. (of. Britich Pat. 925,468) to free the copolymers orthe solvent from water or alcohol, this being of particular advantage,as already a very slight amount of said H-acidic compounds in therecycled solvent would deactivate the catalyst. The copolymers producedby the process of the invention have a very low ash (equal to orinferior to 0.09%) and chlorine content (equal to or inferior to 600p.p.m.).

As catalyst for the copolymerization of ethylene with higher a-olefinsand possibly poly-unsaturated compounds there are used coordinationcatalysts which are soluble in the dispersion medium and comprise (a) Avanadium compound, for example, VOCl VCl vanadium trisacetylacetonate,vanadium hydroxydiacetylacetonate, vanadium naphthenate, vanadiumbenzoate, vanadylester, for example VO(i-C H VO(i-C H VO(OC H )Cl VO(OCH Cl, preferably VOCl (b) An organo-aluminium compound of the formulaA1R X in which R represents an alkyl group with 1 to 16, preferably 2 to6 carbon atoms, X represents halo- (Farbwerke Hoechst). D. Borrmann, R.Wegler German Patent 1,214,211 and Chem. B91. 99 No. 4, 12454251 (1966).

2 Preparation of dimethylketene by H. Bestian and D. Gunther Angew.Chem. 75,841 (1963).

3 F. J. Luknitzku and B. A. Vovsi Z. org. Chim. 2 (1966) No. 10 p. 1895,RA-Patent 176,882 of 28.11.64 (published June 1966).

4 In. V. Zejtman and I. L. Knunjane Izv. Akad. SSSR, 1966, No. 9, pp.1661-1662.

Al R Cl wherein R represents an alkyl group with 1 to 4 carbon atoms,for example Al (C H Cl As organo-aluminium compounds there are likewisesuitable polymeric activators, such as aluminium-isoprenyl, the reactionproduct of aluminium-trialkyls with isopren; and

(c) A halogen-containing, alkyl-substituted fi-lactone.

A substantial, unexpected advantage of the process of the presentinvention is that, because of the extremely high activity of theabove-mentioned modified Ziegler catalysts, rubber-like copolymers ofolefins are obtained with very high space-time yields, as can be seenfrom the examples; this particularly applies to the precipitationpolymerization. This is the more surprising as by addition of increasingamounts of the reactivating compounds mentioned sub (c)after exceedingthe optimum-an increasing inhibition of the polymerization is observed.

Moreover, it is advantageous that with the modified Ziegler catalysts ofthe present invention products are obtained which have uniform chemicaland physical properties, probably because the olefins are more uniformlyreacted during the mixed polymerization and that the vulcanizationproducts thereof have improved mechanical properties.

In the process of British Pat. 925,468 mentioned above ahalogen-containing, alkyl-substituted B-lactone is not used asreactivator and if the copolymer produced in this manner were worked upWithout the use of water, the ash content would also be considerablyhigher because of the higher need of catalyst, and could only be reducedby a subsequent extraction with water, possible after deactivation withalcohol as described above.

In the process of the present invention, however, in which dispersingmedia are used that do not dissolve the rubber, the polymer is simplyfiltered otf, it is completely freed from the solvent and the latter isreconducted into the polymerization vessel. In this manner products areobtained in a multiple yield having a very low ash content.

Furthermore, the process of the present invention offers, in the case ofthe precipitation polymerization, the advantage that the solvent can beused again without further treatment, whereby the major part of theorganoaluminium compound is preserved for the further polymerization andthe reconducted a-olefins are not contaminated or diluted by the gaseousparaflin hydrocarbons formed during the otherwise usual deactivation bymeans of water or alcohol.

In the 'case of solution polymerization the solvent is removed by steamdistillation. Moreover, it is possible to'precipitate the rubber bymeans of miscible non-dissolvers, for example, methanol, ethanol,acetone, and to dry it subsequently.

The highly active mixed catalyst suitable for the copolymerization isadvantageously formed in the polymeriz ation vessel by continuouslyintroducing separate solutions of the-vanadium compound and theorgano-aluminium component in a constant ratio. The halogen-containing,alkyl-substituted B-lactones' used as reactivators can be previouslymixed with the vanadium compound or they can be metered in separately.

As solvents for the catalyst components the above-mentioned dispersionmedia are suitably used.

The molar ratio of organo-aluminium compound to vanadiuincompound mayvary within wide limits, for example, from 20 to 200 and, preferably,from 30 to 100.

When using a halogen-containing, alkyl-substituted fllactone asreactivator according to the process of the present invention, the molarratio of reactivator to vanadium compound should amount to a range offrom to 100, preferably 5 to 20, and the vanadium compound is used inconcentrations in the range of from 0.001 to 0.1 millimole perliter'ofdispersion medium.

When the catalyst components are continuously added to t epolymerization mixture as indicated above and the polymerization iscarried out discontinuously, the indicated concentration is the finalconcentration which is reached only when the mixture already contains acertain amount of polymer.

From Belgian Pat. 695,774 it is known that elastic rubber products whichmay be crosslinked with sulfur can be obtained from said olefincopolymers if into the forming copolymers a small amount of a doublyunsaturated compound is incorporated, the-one double linkage of whichparticipates in the polymerization whereas the other double linkage iskept for an additional sulfur vulcanization. 1

. In U.S.'application Ser. No. 717,760, filed Apr. 1, 1968, notbelonging to the state of the art, there are proposed, amongst others,the following third components: 1,4-cishexadiene, 1,4-trans-hexadiene,alkenyl-norbornenes such as -5-('2- and/or3'-methyl-2-butenyl)-norbornene-2, alkylidene-norbornenes such as5-methylene-norbornene-2, or 5-ethylidenenorbornene-2,dicyclopentadiene, butadiene-l,3 or .isopren.

They are used in suitable amounts so that the formed terpolymer shows aniodine number of up to 50, preferably 3-50. According to the process ofthe present invention terpolymers, of this type can advantageously beprepared, too. v I

In order to produce a rubber having good properties of use aftervulcanization the catalyst systems must be used in the forrnofhomogeneous solutions.

In the process of the presentinvention ethylene can be copolymerizedwith propylene,. butene-l, isobutene, pentene-l, hexene-l,4-methyl-.pentene=1 and other branched orstraight-chain molefins havingup to 8 carbon atoms,

propylene beingpreferred. Ethylene and propylene are copolymerized in aproportion such thatthe copolymers obtained have elastic,'rubber-likeproperties, that is to say the proportion of ethylene in the copolymercan be as high as from.20 to 80% .by-Weigh.t, preferably from 30 to 75%by weight. v v

The copolymerization can be carried out at temperatures in the range'offrom 30 C. to +50 C., preferably l0 C. to +40 C., and under pressures offrom 0 to 30 atmospheres gauge, either batchwise or continuously. Whenthe polymerization is carried out as precipitation polymerization it canbe materialized in the presence of 0.0001 to 10% by weight, calculatedon the dispersion medium, of a finely divided inert solid having a largesurface and a particle size of from 0.005 to 100 microns which does notinhibit the polymerization activity and is insoluble both in thedispersion medium and the separating polymerization product.

Suitable additives of this kind are, for example, the followinginorganic compounds:

chlorides, for example, NaCl and KC],

fluorides, for example, NaF, CaF KFBF 2KF'SiF Na AlF sulfates, forexample, K Na SO CaSO BaSO glauberite, nitrates, for example, NaNO KNOphosphates, for example, Ca (PO apatite, hydroxylapatite,

carbonates, for example, CaCO MgCO Na CO K 00 ZIICO3,

silicates, for example, talcum, kaolinite, SiO for example in the formof xerogels, diatomite and Aerosil (registered trademark),

aluminium silicates, for example, feldspar and oligoklas,

aluminates, for example, spinel and zinc spinel,

borates, for example, Na B O- oxides, for example, Al O AlOOH, Fe O PbO,TiO

ZnO, CaO, MgO.

Furthermore there are suitable as additives finely divided polymers, forexample polyethylene, polypropylene, poly- 4-methyl-pentene-l, orpolyacrylonitrile.

When applying the precipitation polymerization according to the processof the present invention, the polymerization is carried out in methylenechloride, ethyl chloride, 1,2-dichloro-ethane, 1,2-dichloropropane,1,1,2-trifluorotrichloroethane or other halohydrocarbons, preferablymethylene chloride and 1,2-dichloroethane as dispersion medium, as faras they do not dissolve the copolymer under the reaction conditions.

When applying the solution polymerization the following solvents areused, for example: aliphatic, cycloaliphatic, aromatic,aliphatic-aromatic hydrocarbons, especially hexane, heptane,cyclohexane, benzene, toluene and halogenated hydrocarbons dissolvingthe rubber, for instance tetrachloroethylene; hydrogenated Diesel oilfractions may likewise be used.

The polymerization can also be carried out in liquid propylene.

The polymers can be crosslinked using organic peroxides, if desired withthe addition of sulfur, at temperatures in the range of from C. to 240C. When diolefiins are incorporated into the polymers by polymerizationthe vulcanization can be realized by means of sulfur as usually added inrubber industries or of sulfur compounds and accelerators, by heating to100-240 C. within a period of from several minutes to several hours. Thefollowing examples illustrate the invention:

EXAMPLE 1 Solution polymerization in hexane Discontinuouscopolymerization of ethylene and propylene in hexane with varying molarratios of fi S-bis-trivchloromethyl-,B-propiolactone to vanadiumoxytrichloride. In a glass vessel having a capacity of 3.5 liters,provided with a perforated blade stirrer of stainless steel, two. groundin dropping funnels, a reflux condenser with connected mercury excesspressure. valve, a gas inlet tube and thermometer, 2.8 liters of hexanepreviously purified over a column with potassium hydroxide and silicagelare saturated with exclusion of air and moisture, at 15 C. andatmospheric pressure, while stirring, with a gas mixture consisting of 1part by volume of ethylene and 2 parts by volume of propylene. Aftercare has thus been taken that the monomer mixture has the rightcomposition for the production of uniform products, VOCl (0.2 millimolein 100 milliliters of hexane) and ethyl-aluminium-sesquichloride (20millimoles Al in 100 milliliters of hexane) are uniformly dropped within100 minutes at 15 C. into the hexane saturated with ethylene andpropylene in a ratio by volume of 1:2. The monomer mixture(ethylene/propylene=2:l) is then introduced in an amount to compensatepressure. The amount of fifi-bis-trichloromethyl-fl-propiolactone(=HCPl) mentioned in Table 1 is then added to the solution ofvanadium-oxytrichloride. The copolymer is obtained in the form of asolution; by removal of the solvent it is precipitated by means of steamand dried at 50 C. under reduced pressure.

The yield and the properties of the products obtained with the varyingratios of I-ICPl:vanadium-oxytrichloride are indicated in Table 1. Theproducts obtained can be vulcanized with peroxides by the usual methods.They are amorphous, as results from measurements by differentialthermo-analysis.

TABLE 1 saturated with exclusion of air and moisture, at 15 C. and underatmospheric pressure, while stirring, with a gas mixture consisting of 5parts by volume of ethylene and 6 parts by volume of propylene. When,prior to the start of polymerization the monomer mixture has the rightcomposition for the production of uniform products 0.02 millirnol ofVOCl are at first added at 15 C. to the methylene-chloride saturatedWith ethylene and propylene in a ratio by volume of 5:6.Ethyl-aluminium-sesquichloride (a solution of 20 millimoles of Al in 100milliliters of methylene-chloride) is then dropwise added, until thepolymerization sets in, detectable by the subatmospheric pressure formedin the reaction vessel. The monomer mixture (ethylene:propylene=2:1) isadded in an amount to compensate pressure and VOCl (0.18 millimole in100 milliliters of methylene-chloride) and ethylaluminium-sesquichloride(20 millimoles of A1 in 100 milliliters of methylene-chloride) areuniformly added dropwise to the system within 100 minutes. The amount 20of HCPL indicated in Table 2 is then added to the vana- Discontinuouseopolymerization of ethylene and propylene in hexane with varying molarratios of tLfl-bls-tr1chloromethyl-fl-propiolactone to vanadiumoxytrichloride General reaction conditions:

Solvent: Hexane Molar ratio: Al:V=60: 1 V-concentration: 0.2 millimole/3liters of hexane Polymerization temperature: +15 0.

HCPL- Catalyst vanadium efiiciency oxytri- (grams of Mooney Percentchloride polymer] viscosinsol- (molar Yield millimole ity Propyl in ublein Example ratio) (g-) of V 01) n red I ML4 polymer toluene n red:solution.

'- Determined according to DIN 53 523 at 100 0.

EXAMPLE 2 Precipitation polymerization in methylene-chlorideDiscontinuous copolymerization of ethylene and propylene inmethylene-chloride at varying molar ratios of fifi-bis-(trichloromethyl) p propiolactone (:HCPI):vanadium-oxytrichloride.

reduced specific viscosity, measured at 135 C. in 0.1%dekahydrenaphthalene from measurements by differential thermo-analysis.

TABLE 2 Discontinuous copolymerization of ethylene and propylene inmethylene chloride with varying molar ratios of 6,3-bis-propiolacto11e(HCPL): vanadium oxytrichloride (cf. also FIG. 1) (trichloromethyl) 9-General reaction conditions:

Dispersion medium: Methylene chloride Molar ratio: AlzV=z1V-concentration: 0.1 millimole/liter of methylene chloride Polymeriz.temperature: +15 C.

HCPL- Catalyst vanadiumefliciency Propylene oxytri- (g. of in polym.Percent chloride polym./ Mooney (percent insol- (molar Yield llimolevise, by uble in Example ratio) (g.) 0 Ola) a red 1 ML4 weight) toluene1 ured: reduced specific viscosity, measured at C. in 0.1%dekahydronaphthalene solution.

2 Determined according to DIN 53 523 at 100 C. 3 Comparison test.

In a glass vessel having a capacity of 3 liters, provided with aperforated blade stirrer of stainless steel, two ground in droppingfunnels, a reflux condenser with connected mercury excess pressurevalve, a gas inlet tube EXAMPLE 3 Precipitation polymerization inmethylene-chloride Discontinuous copolymerization of ethylene andpropyland thermometer, 1.8 liter of methylene chloride are 75 one inmethylene-chloride with varying molar ratios of 10 of said oc-OlCfiIlStogether with a diolefin in an amount such that the terpolymer formedhas an iodine number not greater than 50, in the presence of inertsolvents or dispersion media, the copolymerization being carried outunder pressures in the range of from to 30 atmospheres gauge and attemperatures in the range of from 30 to +50 C., with coordinationcatalysts of 3- to -valent vanadium compounds and organo-aluminumcompounds, 'both soluble in the inert solvent or dispersion mediumDiscontinuous copolymerization ofethylene and propylene inmethylene-chloride with varying ratios ofB-trichloromethyl-fl-propiolactone (TCPL) (cf. also FIG. 2)

General reaction conditions:

Dispersion medium: Methylene chloride Molar ratio: A1:V=100;1V-coneentration: 0.1 millimole/liter Polymerization temperature: +15 C.

TCPL/ Catalyst vanadium efficiency C3 in oxytii- (g. of polymer Percentchloride polym. Mooney (Percent insol- (molar Yield millimole viscosity,by uble in Example ratio) (g.) of V0013) 1 red 1 ML4 2 weight) tolueneSolution. 4

2 Determined according to 3 Comparison test. I

EXAMPLE 4 Precipitation polymerization in methylene-chlorideDiscontinuous terpolymerization of ethylene/ propylene and'5-ethylidene-norbornene-2 in methylene-chloride with varyingmolar'ratios of fi-trichloro-methyl- 8-propiolactone (TCPL) to vanadiumoxytrichloride.

The copolymerization is carried out as described in Example 3','but witha taking up of 10 liters of gaseous ethylene per hour, l'millilit er ofa solution of 15.1 milliliters of 5-ethylidene-n0rbornene-(2) in 100milliliters of methylene-chloride is dropwise added duringpolymerization. With this dosage there is obtained an unsaturatedethylene/propylene rubber of 3.84.2=* (iodometrically determined) whichafter vulcanization with a usual sulfur accelerator system yieldsvulcanized products showing good static and dynamic vulcanizationproperties.

The products obtained show the following properties:

Mooney viscosity ML =60120 Percent by weight of propylene in the polymer(IR-spectroscopically determined) =45 Percent by weight insoluble intoluene 0.1%

TABLE 4 DIN 53 523 at 100 C.

Catalyst [grams of TCPL=VOC1 polymer/milli- Example (molar ratio) Yield[g.] mole of V001 I claim:

1. Process for the copolymerization of ethylene with a-olefins of theformula RCH=CH wherein R represents an aliphatic branched or straightchained hydrocarbon radical with less than 7 carbon atoms, or with oneused, with stirring or other mechanical agitation, which comprisescarrying out the polymerization (1) by using the vanadium compounds inconcentrations in the range of from 0.001 to 0.1 millimole per liter ofinert solvent or dispersion medium,

(2) by using organo-aluminum compounds the molar ratio of aluminum tovanadium of which being in the range of from 20:1 to 200:1,

(3) in the presence of monoor di-trihalomethyl substituted fi-lactonesas rcactivators, the molar ratio of reactivator to vanadium compoundbeing in the range of from 5:1 to :1 and wherein the halo substituent ofthe halomethyl group is chloro, bromo, or fluoro.

2. Process as claimed in claim 1 wherein the molar ratio of aluminum tovanadium in the coordination catalysts amounts to 30:1 to 100:1.

3. Process as claimed in claim 1 wherein the molar ratio of reactivatorto vanadium compound amounts to 5 :1 to 20:1. 7

4. Process as claimed in claim 1 wherein vanadium oxytrichloride is usedas vanadium compound.

5. Process as claimed in claim 1 wherein ethyl-aluminium-sesquichlorideis used as aluminium compound.

6. Process as claimed in claim 1 whereinfl-trichloromethyl-B-propiolactone or fi e-bis-(trichloromethyl)48-propiolactone is used as reactivator compound.

7. Process as claimed in claim 1 wherein ethylene is copolymerized withpropylene or isobutene.

8. Process as claimed in claim 1 wherein aliphatic :halohydrocarbons areused as dispersion medium.

9. Process as claimed in claim 1 wherein methylene chloride or 1,2dichloro-ethane are used as dispersion medium.

10. Process as claimed in claim 1 wherein hexane is used as solvent.

11. Process as claimed in claim 1 wherein 1,4-cis-hexadiene,1,4-trans-hexadiene or dicyclopentadiene are used as diolefin. v

12. Process as claimed in claim 1 wherein an alkenylnorbornene is usedas diolefin.

13. Process as claimed in claim 1 wherein 5-(2'-methyl- 2-butenyl-norbornene-2 or 2-( 3-methyl-2'-butenyl) norbornene-2 or mixtures ofboth compounds are used as diolefin.

1 1 1 2 14. Process as claimed in claim 1 wherein an alkylidene-3,380,981 4/ 1968 Miller 260-93] norbornene is used as diolefin.3,397,196 8/ 1968 Shearer 260-93] 15. Process as claimed in claim 1wherein 5-methylene- 3,415,801 12/1968 Coover 260--93.7 norbornene-Z orS-ethylidene-norfbornene-Z is used as diolefill- 6 JOSEPH L. SCHOFER,Primary Examiner References Cited UNITED STATES PATENTS E. J. SMITH,Assistant Examiner 3,149,097 9/1964 Coover -v 26093.7 3,301,834 1/1967Christmas 260-805 10 US.

3,365,434 1/1968 Coover 260'-93.7 252-429 B; 26088.2, 94.9 C

